Chip package and manufacturing method thereof

ABSTRACT

A chip package includes a chip, an isolation layer, a redistribution layer, a passivation layer, and an encapsulation layer. The chip has a sensor, a conductive pad, a through hole, a top surface, and a bottom surface that is opposite the top surface. The sensor and the conductive pad are located on the top surface, and the conductive pad is in the through hole. The isolation layer is located on the bottom surface of the chip and a sidewall that surrounds the through hole. The redistribution layer is located on the isolation layer, and is in electrical contact with the conductive pad. The passivation layer is located on the isolation layer and the redistribution layer. The encapsulation layer is located on the top surface of the chip and covers the sensor and the conductive pad, and has a flat surface facing away from the chip.

RELATED APPLICATIONS

This application claims priority to U.S. provisional Application Ser.No. 62/519,022, filed Jun. 13, 2017, which is herein incorporated byreference.

BACKGROUND Field of Invention

The present invention relates to a chip package and a manufacturingmethod of the chip package.

Description of Related Art

The process of packaging a chip is an important step for formingelectronic products. A chip package can protect the chip therein toprevent the chip from environmental pollution, and it also provideselectrical connection paths between inner electronic elements of thechip and external devices.

During an electronic product capable of sensing fingerprints being usedby a user, moisture or oil stains easily remain on the electronicproduct, thereby causing the chip package in the electronic product tobe polluted. In addition, when the electronic product is operated, asensor is easily physically damaged, thereby reducing the lifespan ofthe electronic product. Moreover, the capacitance of a typicalelectronic product is easily attenuated, thereby affecting the sensingcapability of the typical electronic product, such as the capability ofsensing fingerprints.

SUMMARY

An aspect of the present invention is to provide a chip package.

According to an embodiment of the present invention, a chip packageincludes a chip, a first isolation layer, a redistribution layer, apassivation layer, and an encapsulation layer. The chip has a sensor, aconductive pad, a through hole, a top surface, and a bottom surface thatis opposite the top surface. The sensor and the conductive pad arelocated on the top surface, and the conductive pad is in the throughhole. The first isolation layer is located on the bottom surface of thechip and a sidewall that surrounds the through hole. The redistributionlayer is located on the first isolation layer and is in electricalcontact with the conductive pad that is in the through hole. Thepassivation layer is located on the first isolation layer and theredistribution layer. The passivation layer on the bottom surface of thechip has an opening, and a portion of the redistribution layer is in theopening. The encapsulation layer is located on the top surface of thechip and covers the sensor and the conductive pad. The encapsulationlayer has a flat surface facing away from the chip.

An aspect of the present invention is to provide a manufacturing methodof a chip package.

According to an embodiment of the present invention, a manufacturingmethod of a chip package includes forming a temporary bonding layer on acarrier, forming an encapsulation layer on a top surface of a wafer oron the temporary bonding layer, bonding the carrier to the wafer, inwhich the encapsulation layer and the temporary bonding layer arelocated between the wafer and the carrier, and the encapsulation layercovers a sensor and a conductive pad of the wafer, patterning a bottomsurface of the wafer to form a through hole, in which the conductive padis exposed through the through hole, forming an isolation layer on thebottom surface of the wafer and a sidewall of the through hole, forminga redistribution layer on the isolation layer and the conductive padthat is in the through hole, forming a passivation layer on theisolation layer and the redistribution layer, in which the passivationlayer has an opening, and a portion of the redistribution layer is inthe opening, and removing the temporary bonding layer and the carrier.

An aspect of the present invention is to provide a chip package.

According to an embodiment of the present invention, a chip packageincludes a chip, a molding compound, a redistribution layer, apassivation layer, and an encapsulation layer. The chip has a sensor, aconductive pad, a top surface, a bottom surface that is opposite the topsurface, and a lateral surface that adjoins the top surface and thebottom surface. The sensor and the conductive pad are located on the topsurface, and the conductive pad protrudes from the lateral surface. Themolding compound covers the bottom surface and the lateral surface ofthe chip, and has a through hole. The conductive pad is in the throughhole. The redistribution layer is located on the molding compound and isin electrical contact with the conductive pad that is in the throughhole. The passivation layer is located on the molding compound and theredistribution layer. The passivation layer on the bottom surface of thechip has an opening, and a portion of the redistribution layer is in theopening. The encapsulation layer is located on the top surface of thechip and covers the sensor and the conductive pad. The encapsulationlayer has a flat surface facing away from the chip.

An aspect of the present invention is to provide a manufacturing methodof a chip package.

According to an embodiment of the present invention, a manufacturingmethod of a chip package includes forming a temporary bonding layer on acarrier, forming an encapsulation layer on a top surface of a wafer oron the temporary bonding layer, bonding the carrier to the wafer, inwhich the encapsulation layer and the temporary bonding layer arelocated between the wafer and the carrier, and the encapsulation layercovers a sensor and a conductive pad of the wafer, patterning a bottomsurface of the wafer to form a dicing trench, in which the conductivepad is exposed through the dicing trench, molding a molding compound tocover the bottom surface of the wafer and the dicing trench, forming athrough hole in the molding compound by laser drilling, in which theconductive pad is in the through hole, forming a redistribution layer onthe molding compound and the conductive pad that is in the through hole,forming a passivation layer on the molding compound and theredistribution layer, in which the passivation layer has an opening, anda portion of the redistribution layer is in the opening, and removingthe temporary bonding layer and the carrier.

In the aforementioned embodiments of the present invention, theencapsulation layer is located on the top surface of the chip and coversthe sensor and the conductive pad, thereby preventing the sensor and theconductive pad from being polluted by moisture, oil stain, or dust.Moreover, the encapsulation layer has the flat surface facing away fromthe chip, and thus the top of the chip package is configured with fullplanarization. Such a design is a convenient factor for assembly, andcan improve a tactile sensation for users. In addition, when the chippackage is a fingerprint sensing device, the encapsulation layer havinga suitable thickness and a suitable dielectric constant can preventcapacitance attenuation, thereby improving the detect sensitivity of thechip package for fingerprints.

It is to be understood that both the foregoing general description andthe following detailed description are by examples, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the followingdetailed description of the embodiments, with reference made to theaccompanying drawings as follows:

FIG. 1A is a top view of a chip package according to one embodiment ofthe present invention;

FIG. 1B is a cross-sectional view of the chip package taken along line1B-1B shown in FIG. 1A;

FIG. 2 is a cross-sectional view of a chip package according to oneembodiment of the present invention;

FIGS. 3 to 8 are cross-sectional views of a manufacturing method of achip package according to one embodiment of the present invention;

FIG. 9 is a cross-sectional view of a chip package according to oneembodiment of the present invention;

FIG. 10A is a cross-sectional view of a chip package according to oneembodiment of the present invention;

FIG. 10B is a cross-sectional view of a chip package according to oneembodiment of the present invention;

FIGS. 11 to 15B are cross-sectional views of a manufacturing method of achip package according to some embodiments of the present invention;

FIG. 16 is a cross-sectional view of a chip package according to oneembodiment of the present invention;

FIG. 17A is a cross-sectional view of a chip package according to oneembodiment of the present invention;

FIG. 17B is a cross-sectional view of a chip package according to oneembodiment of the present invention; and

FIGS. 18 to 22 are cross-sectional views of a manufacturing method of achip package according to some embodiments of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

FIG. 1A is a top view of a chip package 100 according to one embodimentof the present invention. FIG. 1B is a cross-sectional view of the chippackage 100 taken along line 1B-1B shown in FIG. 1A. As shown in FIG. 1Aand FIG. 1B, the chip package 100 includes a chip 110, an isolationlayer 120, a redistribution layer 130, a passivation layer 140, and anencapsulation layer 150. The chip 110 has a sensor 112, a conductive pad114, a through hole 116, a top surface 111, and a bottom surface 113that is opposite the top surface 111. The sensor 112 and the conductivepad 114 are located on the top surface 111 of the chip 110, and theconductive pad 114 is in the through hole 116. The isolation layer 120is located on the bottom surface 113 of the chip 110 and a sidewall 115that surrounds the through hole 116. The redistribution layer 130 islocated on the isolation layer 120, and is in electrical contact withthe conductive pad 114 that is in the through hole 116. The passivationlayer 140 is located on the isolation layer 120 and the redistributionlayer 130. The passivation layer 140 on the bottom surface 113 of thechip 110 has an opening 142, and a portion of the redistribution layer130 is in the opening 142. The encapsulation layer 150 is located on thetop surface 111 of the chip 110 and covers the sensor 112 and theconductive pad 114. Moreover, the encapsulation layer 150 has a flatsurface 152 that faces away from the chip 110.

In this embodiment, the chip 110 may be made of silicon. The sensor 112is a fingerprint sensor. However, in another embodiment, the sensor 112may be an image sensor, and the present invention is not limited in thisregard. The redistribution layer 130 of the chip package 100 is exposedthrough the opening 142 of the passivation layer 140, and may be used toelectrically connect to a conductive structure of an external electronicelement (e.g., a printed circuit board). Such a configuration isdescribed as a land grid array (LGA).

Since the encapsulation layer 150 is located on the top surface 111 ofthe chip 110 and covers the sensor 112 and the conductive pad 114, thesensor 112 and the conductive pad 114 may be prevented from beingpolluted by moisture, oil stain, or dust. As a result, the yield andreliability of the chip package 100 can be improved, and the lifespan ofthe chip package 100 can be extended. Moreover, because the chip package100 has the encapsulation layer 150, designers may select the chip 110having a small thickness to reduce the total thickness of the chippackage 100 but not to lead the chip 110 to be broken. In addition, theencapsulation layer 150 has the flat surface 152 that faces away fromthe chip 110, and thus the top of the chip package 100 is configuredwith full planarization. Such a design is a convenient factor forassembly, and can improve a tactile sensation for users. When the chippackage 100 is a fingerprint sensing device, the encapsulation layer 150having a suitable thickness and a suitable dielectric constant canprevent capacitance attenuation, thereby improving the detectsensitivity of the chip package 100 for fingerprints. For example, thethickness of the encapsulation layer 150 may be in a range from 5 μm to40 μm, and the dielectric constant of the encapsulation layer 150 may begreater than 5.

Furthermore, the chip package 100 may further include an isolation layer160. The isolation layer 160 is located on the top surface 111 of thechip 110, and is covered by the encapsulation layer 150.

FIG. 2 is a cross-sectional view of a chip package 100 a according toone embodiment of the present invention. The chip package 100 a includesthe chip 110, the isolation layer 120, the redistribution layer 130, thepassivation layer 140, and the encapsulation layer 150. The differencebetween this embodiment and the embodiment shown in FIG. 1B is that thechip package 100 a further includes a conductive structure 170. Theconductive structure 170 is located on the redistribution layer 130 thatis in the opening 142 of the passivation layer 140, and protrudes fromthe passivation layer 140. The conductive structure 170 may be used toelectrically connect conductive contacts of an external electronicelement (e.g., a printed circuit board). Such a configuration is a ballgrid array (BGA).

In the following description, manufacturing methods of the chip package100 of FIG. 1B and the chip package 100 a of FIG. 2 will be described.

FIGS. 3 to 8 are cross-sectional views of a manufacturing method of achip package according to one embodiment of the present invention. Asshown in FIG. 3, first of all, a temporary bonding layer 210 is formedon a carrier 220, and the encapsulation layer 150 is formed on the topsurface 111 of a wafer 110 a or on the temporary bonding layer 210. Thewafer 110 a is referred to as a semiconductor structure which is not yetdivided into plural chips 110 (see FIG. 1B and FIG. 2), such as asilicon wafer. Thereafter, the carrier 220 may be bonded to the wafer110 a through the temporary bonding layer 210 and the encapsulationlayer 150, such that the encapsulation layer 150 and the temporarybonding layer 210 are located between the wafer 110 a and the carrier220, and the encapsulation layer 150 covers the sensor 112 and theconductive pad 114 of the wafer 110 a. Afterwards, a grinding treatmentmay be performed on a bottom surface 113 of the wafer 110 a to reducethe thickness of the wafer 110 a as deemed necessary.

As shown in FIG. 4, after bonding the carrier 220 to the wafer 110 a andthe grinding treatment, the bottom surface 113 of the wafer 110 a ispatterned to form the through hole 116, such that the conductive pad 114is exposed through the through hole 116. In this step, the wafer 110 amay be patterned by photolithography. For example, photolithography mayinclude exposure, development, and etch processes. In this embodiment,the bottom surface of the wafer 113 may be patterned to form a dicingtrench 105, such that a portion of the wafer 110 a is located betweenthe dicing trench 105 and the through hole 116. In the subsequentmanufacturing process, the dicing trench 105 may be used as a cuttingpath for a cutting tool, as shown in FIG. 8.

As shown in FIG. 5, after the through hole 116 is formed, the isolationlayer 120 may be formed on the bottom surface 113 of the wafer 110 a,the sidewall 115 of the through hole 116, and the conductive pad 114that is in the through hole 116 through chemical vapor deposition (CVD).Thereafter, an etch process is performed on the isolation layer 120 toremove the isolation layer 120 that is on the conductive pad 114. Asshown in FIG. 6, after the formation of the isolation layer 120, theredistribution layer 130 may be formed on the isolation layer 120 andthe conductive pad 114 that is in the through hole 116.

As shown in FIG. 7, next, the passivation layer 140 may be formed on theisolation layer 120 and the redistribution layer 130, and a portion ofthe passivation layer 140 may be located in the dicing trench 105.Moreover, the passivation layer 140 may be patterned to have the opening142, such that a portion of the redistribution layer 130 is in theopening 142. As shown in FIG. 8, after the formation of the passivationlayer 140, the temporary bonding layer 210 and the carrier 220 may beoptionally removed. For example, ultraviolet light may be utilized toirradiate the temporary bonding layer 210, thereby eliminating theadhesion of the temporary bonding layer 210. Afterwards, theencapsulation layer 150 and the passivation layer 140 may be cut alongthe dicing trench 105. In other words, the encapsulation layer 150 andthe passivation layer 140 may be cut along line L-L. After the dicingstep, the chip package 100 of FIG. 1B can be obtained.

In addition, before the removal of the temporary bonding layer 210 andthe carrier 220, the conductive structure 170 (see FIG. 2) may be formedon the redistribution layer 130 that is in the opening 142 of thepassivation layer 140, such that the conductive structure 170 may beelectrically connected to the conductive pad 114 through theredistribution layer 130. After the formation of the conductivestructure 170, the temporary bonding layer 210 and the carrier 220 maybe optionally removed, and the encapsulation layer 150 and thepassivation layer 140 are cut along line L-L. After the dicing step, thechip package 100 a of FIG. 2 can be obtained.

It is to be noted that the connection relationship of the aforementionedelements will not be repeated. In the following description, other typesof the chip packages will be described.

FIG. 9 is a cross-sectional view of a chip package 100 b according toone embodiment of the present invention. The chip package 100 b includesthe chip 110, the isolation layer 120, the redistribution layer 130, thepassivation layer 140, and the encapsulation layer 150. The differencebetween this embodiment and the embodiment shown in FIG. 1B is that thechip 110 of the chip package 100 b further has a concave portion 118.The through hole 116 is higher than the concave portion 118 in position.The concave portion 118 has two adjacent surfaces 117 and 119, and thesurface 117 of the concave portion 118 adjoins the sidewall 115 of thethrough hole 116, and the surface 119 of the concave portion 118 adjoinsthe bottom surface 113 of the chip 110. An obtuse angle θ is formedbetween the two surfaces 117 and 119 of the concave portion 118. Thesidewall 115 of the through hole 116, the two surfaces 117 and 119 ofthe concave portion 118, and the bottom surface 113 of the chip 110present a step profile. Therefore, the redistribution layer 130 extendsfrom the conductive pad 114 to the bottom surface 113 of the chip 110along the sidewall 115 of the through hole 116 and the two surfaces 117and 119 of the concave portion 118, such that the redistribution layer130 presents a step profile to prevent from being easily broken. In thisembodiment, the redistribution layer 130 is exposed through the opening142 of the passivation layer 140, and thus the chip package 100 b has aland grid array.

FIG. 10A is a cross-sectional view of a chip package 100 c according toone embodiment of the present invention. The chip package 100 c includesthe chip 110, the isolation layer 120, the redistribution layer 130, thepassivation layer 140, and the encapsulation layer 150. The differencebetween this embodiment and the embodiment shown in FIG. 9 is that thechip package 100 c further includes the conductive structure 170. Theconductive structure 170 is located on the redistribution layer 130 thatis in the opening 142 of the passivation layer 140. In this embodiment,the conductive structure 170 protrudes from the passivation layer 140,and the chip package 100 c has a ball grid array.

FIG. 10B is a cross-sectional view of a chip package 100 c′ according toone embodiment of the present invention. The chip package 100 c′includes the chip 110, the isolation layer 120, the redistribution layer130, the passivation layer 140, and the encapsulation layer 150. Thedifference between this embodiment and the embodiment shown in FIG. 9 isthat the chip package 100 c′ further includes a conductive structure 170a and a molding compound 190. The conductive structure 170 a is locatedon the redistribution layer 130 that is in the opening 142 of thepassivation layer 140. In this embodiment, the conductive structure 170a has a bottom surface 172 facing away from the redistribution layer130. The molding compound 190 covers the passivation layer 140 andsurrounds the conductive structure 170 a. The molding compound 190 has abottom surface 192 facing away from the passivation layer 140, and thebottom surface 192 of the molding compound 190 and the bottom surface172 of the conductive structure 170 a are at the same horizontal level.

In the following description, manufacturing methods of the chip package100 b of FIG. 9 and the chip package 100 c of FIG. 10A will bedescribed.

FIGS. 11 to 15B are cross-sectional views of a manufacturing method of achip package according to some embodiments of the present invention. Asshown in FIG. 3 and FIG. 11, first of all, the temporary bonding layer210 is formed on the carrier 220, and the encapsulation layer 150 isformed on the top surface 111 of the wafer 110 a or on the temporarybonding layer 210. Thereafter, the carrier 220 may be bonded to thewafer 110 a through the temporary bonding layer 210 and theencapsulation layer 150, and a grinding treatment may be performed onthe bottom surface 113 of the wafer 110 a to reduce the thickness of thewafer 110 a as deemed necessary. After bonding the carrier 220 to thewafer 110 a and the grinding treatment, the bottom surface 113 of thewafer 110 a may be patterned to form the through hole 116, such that theconductive pad 114 is exposed through the through hole 116. In thisstep, the bottom surface 113 of the wafer 110 a is patterned to form theconcave portion 118, and the concave portion 118 has two adjacentsurfaces 117 and 119. Thereafter, the surface 117 of the concave portion118 is patterned to form the through hole 116, such that the twosurfaces 117 and 119 of the concave portion 118 are respectively adjointhe sidewall 115 of the through hole 116 and the bottom surface 113 ofthe wafer 110 a. For example, a two-step etch treatment is used to formthe concave portion 118 and the through hole 116 in sequence. Moreover,in the step of forming the through hole 116, the wafer 110 a may bepatterned to form the dicing trench 105, such that a portion of thewafer 110 a is located between the dicing trench 105 and the throughhole 116. In the subsequent manufacturing process, the dicing trench 105may be used as a cutting path for a cutting tool, as shown in FIG. 15A.

As shown in FIG. 12, after the formations of the concave portion 118 andthe through hole 116, the isolation layer 120 may be formed on thebottom surface 113 of the wafer 110 a, the surfaces 117 and 119 of theconcave portion 118, the sidewall 115 of the through hole 116, and theconductive pad 114 that is in the through hole 116. Thereafter, an etchtreatment is performed on the isolation layer 120 to remove theisolation layer 120 that is on the conductive pad 114. As shown in FIG.13, after the isolation layer 120 is formed, the redistribution layer130 may be formed on the isolation layer 120 and the conductive pad 114that is in the through hole 116.

As shown in FIG. 14, next, the passivation layer 140 may be formed onthe isolation layer 120 and the redistribution layer 130, and a portionof the passivation layer 140 may be located in the dicing trench 105.Moreover, the passivation layer 140 may be patterned to have the opening142, such that a portion of the redistribution layer 130 is in theopening 142. As shown in FIG. 15A, after the formation of thepassivation layer 140, the temporary bonding layer 210 and the carrier220 may be optionally removed. For example, ultraviolet light may beutilized to irradiate the temporary bonding layer 210, therebyeliminating the adhesion of the temporary bonding layer 210. Afterwards,the encapsulation layer 150 and the passivation layer 140 may be cutalong the dicing trench 105. In other words, the encapsulation layer 150and the passivation layer 140 may be cut along line L-L. After thedicing step, the chip package 100 b of FIG. 9 can be obtained.

In addition, before the removal of the temporary bonding layer 210 andthe carrier 220, the conductive structure 170 (see FIG. 10A) may beformed on the redistribution layer 130 that is in the opening 142 of thepassivation layer 140, such that the conductive structure 170 may beelectrically connected to the conductive pad 114 through theredistribution layer 130. After the formation of the conductivestructure 170, the temporary bonding layer 210 and the carrier 220 maybe optionally removed, and the encapsulation layer 150 and thepassivation layer 140 are cut along line L-L. After the dicing step, thechip package 100 c of FIG. 10A can be obtained.

In another embodiment, as shown in FIG. 15B, the conductive structure170 may be formed on the redistribution layer 130 that is in the opening142 of the passivation layer 140 and then the molding compound 190 isformed to cover the passivation layer 140 and the conductive structure170 before the dicing step of FIG. 15A. Thereafter, a grinding treatmentmay be performed on the molding compound 190 and the conductivestructure 170 from the bottom surface 192 of the molding compound 190.As a result, the chip package 100 c′ having the conductive structure 170a of FIG. 10B can be obtained after a dicing step.

FIG. 16 is a cross-sectional view of a chip package 100 d according toone embodiment of the present invention. The chip package 100 d includesthe chip 110, a molding compound 180, the redistribution layer 130, thepassivation layer 140, and the encapsulation layer 150. The chip 110 hasthe sensor 112, the conductive pad 114, the top surface 111, the bottomsurface 113 that is opposite the top surface 111, and a lateral surface109 that adjoins the top surface 111 and the bottom surface 113. Thesensor 112 and the conductive pad 114 are located on the top surface 111of the chip 110, and the conductive pad 114 protrudes from the lateralsurface 109. The molding compound 180 covers the bottom surface 113 andthe lateral surface 109 of the chip 110, and has a through hole 182. Theconductive pad 114 is in the through hole 182. The redistribution layer130 is located on the molding compound 180 and is in electrical contactwith the conductive pad 114 that is in the through hole 182. Thepassivation layer 140 is located on the molding compound 180 and theredistribution layer 130. In this embodiment, the passivation layer 140and the molding compound 180 may be made of the same material, such asepoxy, but the present invention is not limited in this regard. Thepassivation layer 140 on the bottom surface 113 of the chip 110 has anopening 142, and a portion of the redistribution layer 130 is in theopening 142. In this embodiment, the redistribution layer 130 is exposedthrough the opening 142 of the passivation layer 140, and thus the chippackage 100 d has a land grid array. The encapsulation layer 150 islocated on the top surface 111 of the chip 110 and covers the sensor 112and the conductive pad 114. The encapsulation layer 150 has the flatsurface 152 that faces away from the chip 110. The thickness of theencapsulation layer 150 may be in a range from 5 μm to 40 μm, and thedielectric constant of the encapsulation layer 150 may be greater than5.

In this embodiment, the molding compound 180 has a surface 184 thatsurrounds the through hole 182 and a surface 186 that faces away fromthe bottom surface 113 of the chip 110, and the surface 184 isperpendicular to the surface 186. Moreover, the redistribution layer 130extends from the conductive pad 114 to the surface 186 of the moldingcompound 180 along the surface 184 of the molding compound 180. In thisembodiment, the chip package 100 d may further include the isolationlayer 160. The isolation layer 160 is located on the top surface 111 ofthe chip 110, and is covered by the encapsulation layer 150.

FIG. 17A is a cross-sectional view of a chip package 100 e according toone embodiment of the present invention. The chip package 100 e includesthe chip 110, the molding compound 180, the redistribution layer 130,the passivation layer 140, and the encapsulation layer 150. Thedifference between this embodiment and the embodiment shown in FIG. 16is that the chip package 100 e further includes the conductive structure170. The conductive structure 170 is located on the redistribution layer130 that is in the opening 142 of the passivation layer 140. In thisembodiment, the conductive structure 170 protrudes from the passivationlayer 140, and thus the chip package 100 e has a ball grid array.

FIG. 17B is a cross-sectional view of a chip package 100 e′ according toone embodiment of the present invention. The chip package 100 e′includes the chip 110, the isolation layer 120, a redistribution layer130 a, the passivation layer 140, and the encapsulation layer 150. Thedifference between this embodiment and the embodiment shown in FIG. 17Ais that a conductive structure 170 b of the chip package 100 e′ has abottom surface 172 facing away from the redistribution layer 130 a, andthe bottom surface 172 of the conductive structure 170 b is level withthe passivation layer 140. Moreover, a through hole 182 a and theredistribution layer 130 a of the chip package 100 e′ extend to theencapsulation layer 150, in which the redistribution layer 130 a mayfill the through hole 182 a that is in the conductive pad 114 and theencapsulation layer 150.

In the following description, manufacturing methods of the chip package100 d of FIG. 16 and the chip package 100 e of FIG. 17A will bedescribed.

FIGS. 18 to 22 are cross-sectional views of a manufacturing method of achip package according to some embodiments of the present invention. Asshown in FIG. 3 and FIG. 18, first of all, the temporary bonding layer210 is formed on the carrier 220, and the encapsulation layer 150 isformed on the top surface 111 of the wafer 110 a or on the temporarybonding layer 210. Thereafter, the carrier 220 may be bonded to thewafer 110 a through the temporary bonding layer 210 and theencapsulation layer 150, and a grinding treatment may be performed onthe bottom surface 113 of the wafer 110 a to reduce the thickness of thewafer 110 a as deemed necessary. After bonding the carrier 220 to thewafer 110 a and the grinding treatment, the bottom surface 113 of thewafer 110 a may be patterned to form the dicing trench 105, such thatthe conductive pad 114 is exposed through the dicing trench 105. In thesubsequent manufacturing process, the dicing trench 105 may be used as acutting path for a cutting tool, as shown in FIG. 22.

As shown in FIG. 19A, after the formation of the dicing trench 105, themolding compound 180 is molded to cover the bottom surface 113 of thewafer 110 a and the dicing trench 105. Thereafter, the through hole 182is formed in the molding compound 180 by laser drilling, such that theconductive pad 114 is in the through hole 182. As shown in FIG. 20A,after the formation of the through hole 182 of the molding compound 180,the redistribution layer 130 may be formed on the surfaces 184 and 186of the molding compound 180 and the conductive pad 114 that is in thethrough hole 182.

As shown in FIG. 21, next, the passivation layer 140 may be formed onthe molding compound 180 and the redistribution layer 130. Moreover, thepassivation layer 140 may be patterned to have the opening 142, suchthat a portion of the redistribution layer 130 is in the opening 142. Asshown in FIG. 22, after the formation of the passivation layer 140, thetemporary bonding layer 210 and the carrier 220 may be optionallyremoved. For example, ultraviolet light may be utilized to irradiate thetemporary bonding layer 210, thereby eliminating the adhesion of thetemporary bonding layer 210. Afterwards, the encapsulation layer 150,the molding compound 180, and the passivation layer 140 may be cut alongthe dicing trench 105. In other words, the encapsulation layer 150, themolding compound 180, and the passivation layer 140 may be cut alongline L-L. After the dicing step, the chip package 100 d of FIG. 16 canbe obtained.

In addition, before the removal of the temporary bonding layer 210 andthe carrier 220, the conductive structure 170 (see FIG. 17A) may beformed on the redistribution layer 130 that is in the opening 142 of thepassivation layer 140, such that the conductive structure 170 may beelectrically connected to the conductive pad 114 through theredistribution layer 130. After the formation of the conductivestructure 170, the temporary bonding layer 210 and the carrier 220 maybe optionally removed, and the encapsulation layer 150, the moldingcompound 180, and the passivation layer 140 are cut along line L-L.After the dicing step, the chip package 100 e of FIG. 17A can beobtained.

In another embodiment, as shown in FIG. 19B, after the formation of themolding compound 180, the through hole 182 a may be formed in themolding compound 180 by laser drilling, and the through hole 182 apasses through the conductive pad 114 and extends to the encapsulationlayer 150. Thereafter, as shown in FIG. 20B, the redistribution layer130 a is formed not only on the surfaces 184 and 186 of the moldingcompound 180 and the conductive pad 114 that is in the through hole 182a, but also on the encapsulation layer 150 that is in the through hole182 a. Next, after the aforementioned steps of forming the passivationlayer 140 and the conductive structure 170, removing the temporarybonding layer 210 and the carrier 220, and dicing, the chip package 100e′ having the through hole 182 a, the redistribution layer 130 a, andthe conductive structure 170 b of FIG. 17B can be obtained.

Although the present invention has been described in considerable detailwith reference to certain embodiments thereof, other embodiments arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncovers modifications and variations of this invention provided they fallwithin the scope of the following claims.

What is claimed is:
 1. A chip package, comprising: a chip having a sensor, a conductive pad, a top surface, and a bottom surface that is opposite the top surface, wherein the sensor and the conductive pad are located on the top surface; a redistribution layer located on the bottom surface of the chip and in electrical contact with the conductive pad; and an encapsulation layer located on the top surface of the chip and covering the sensor and the conductive pad, wherein the encapsulation layer has a flat surface facing away from the chip.
 2. The chip package of claim 1, wherein the chip has a through hole, and the conductive pad is in the through hole, and the chip package further comprises: an isolation layer located between the chip and the redistribution layer, and located on a sidewall that surrounds the through hole; and a passivation layer located on the isolation layer and the redistribution layer, wherein the passivation layer on the bottom surface of the chip has an opening, and a portion of the redistribution layer is in the opening.
 3. The chip package of claim 2, further comprising: a conductive structure located on the portion of the redistribution layer and protruding from the passivation layer, and having a bottom surface facing away from the redistribution layer; and a molding compound covering the passivation layer and surrounding the conductive structure, and having a bottom surface facing away from the passivation layer, wherein the bottom surface of the molding compound and the bottom surface of the conductive structure are at the same horizontal level.
 4. The chip package of claim 2, wherein the chip has a concave portion that has two adjacent surfaces, and the two surfaces of the concave portion respectively adjoin the sidewall of the through hole and the bottom surface of the chip, and an obtuse angle is formed between the two surfaces of the concave portion.
 5. The chip package of claim 4, wherein the sidewall of the through hole, the two surfaces of the concave portion, and the bottom surface of the chip present a step profile, and the redistribution layer extends from the conductive pad to the bottom surface of the chip along the sidewall of the through hole and the two surfaces of the concave portion, thereby presenting a step profile.
 6. The chip package of claim 1, wherein a thickness of the encapsulation layer is in a range from 5 μm to 40 μm, and a dielectric constant of the encapsulation layer is greater than
 5. 7. The chip package of claim 1, wherein the chip has a lateral surface that adjoins the top surface and the bottom surface, and the conductive pad protrudes from the lateral surface, and the chip package further comprises: a molding compound covering the bottom surface and the lateral surface of the chip, and located between the chip and the redistribution layer, and having a through hole, wherein the conductive pad is in the through hole; and a passivation layer located on the molding compound and the redistribution layer, wherein the passivation layer on the bottom surface of the chip has an opening, and a portion of the redistribution layer is in the opening.
 8. The chip package of claim 7, further comprising: a conductive structure located on the portion of the redistribution layer and protruding from the passivation layer, and having a bottom surface facing away from the redistribution layer, wherein the bottom surface of the conductive structure protrudes from the passivation layer or is level with the passivation layer
 9. The chip package of claim 7, wherein the through hole and the redistribution layer extend to the encapsulation layer.
 10. The chip package of claim 7, wherein the molding compound has a first surface that surrounds the through hole and a second surface that faces away from the bottom surface of the chip, and the first surface is perpendicular to the second surface, and the redistribution layer extends from the conductive pad to the second surface of the molding compound along the first surface of the molding compound.
 11. A manufacturing method of a chip package, comprising: forming a temporary bonding layer on a carrier; forming an encapsulation layer on a top surface of a wafer or on the temporary bonding layer; bonding the carrier to the wafer, wherein the encapsulation layer and the temporary bonding layer are located between the wafer and the carrier, and the encapsulation layer covers a sensor and a conductive pad of the wafer; patterning a bottom surface of the wafer to form a through hole, wherein the conductive pad is exposed through the through hole; forming an isolation layer on the bottom surface of the wafer and a sidewall of the through hole; forming a redistribution layer on the isolation layer and the conductive pad that is in the through hole; forming a passivation layer on the isolation layer and the redistribution layer, wherein the passivation layer has an opening, and a portion of the redistribution layer is in the opening; and removing the temporary bonding layer and the carrier.
 12. The manufacturing method of the chip package of claim 11, further comprising: forming a conductive structure on the portion of the redistribution layer.
 13. The manufacturing method of the chip package of claim 12, further comprising: forming a molding compound covering the passivation layer and the conductive structure; and grinding the molding compound and the conductive structure such that a bottom surface of the molding compound facing away from the passivation layer and a bottom surface of the conductive structure facing away from the redistribution layer are at the same horizontal level.
 14. The manufacturing method of the chip package of claim 11, further comprising: patterning a bottom surface of the wafer to form a dicing trench, wherein a portion of the wafer is located between the dicing trench and the through hole, and a portion of the passivation layer is in the dicing trench.
 15. The manufacturing method of the chip package of claim 14, further comprising: cutting the encapsulation layer and the passivation layer along the dicing trench.
 16. The manufacturing method of the chip package of claim 11, wherein patterning the bottom surface of the wafer to form the through hole comprises: patterning the bottom surface of the wafer to form a concave portion, wherein the concave portion has two adjacent surfaces; and patterning one of the two surfaces of the concave portion to form the through hole, wherein the two surfaces of the concave portion are respectively adjoin the sidewall of the through hole and the bottom surface of the wafer.
 17. A manufacturing method of a chip package, comprising: forming a temporary bonding layer on a carrier; forming an encapsulation layer on a top surface of a wafer or on the temporary bonding layer; bonding the carrier to the wafer, wherein the encapsulation layer and the temporary bonding layer are located between the wafer and the carrier, and the encapsulation layer covers a sensor and a conductive pad of the wafer; patterning a bottom surface of the wafer to form a dicing trench, wherein the conductive pad is exposed through the dicing trench; molding a molding compound to cover the bottom surface of the wafer and the dicing trench; forming a through hole in the molding compound by laser drilling, wherein the conductive pad is in the through hole; forming a redistribution layer on the molding compound and the conductive pad that is in the through hole; forming a passivation layer on the molding compound and the redistribution layer, wherein the passivation layer has an opening, and a portion of the redistribution layer is in the opening; and removing the temporary bonding layer and the carrier.
 18. The manufacturing method of the chip package of claim 17, further comprising: forming a conductive structure on the portion of the redistribution layer, wherein a bottom surface of the conductive structure facing away from the redistribution layer protrudes from the passivation layer or is level with the passivation layer.
 19. The manufacturing method of the chip package of claim 17, further comprising: cutting the encapsulation layer, the molding compound, and the passivation layer along the dicing trench.
 20. The manufacturing method of the chip package of claim 17, further comprising: extending the through hole to the encapsulation layer by laser drilling; and forming the redistribution layer on the encapsulation layer that is in the through hole. 